I have eczema and contact dermatitis and my clothes make me itch. A lot of other things also tend to irritate my skin. Here is a list of some of the things I am sensitive to: red, orange and blue disperse dye, laundry detergents with perfumes or dyes, nylon, polyester, wool, household cleaning products, water repellant, wrinkle free and stain resistance fabric finishes.
It’s very hard for me to wear most clothes, especially dark-colored clothes. My secret, at least in the cooler months, is to wear white or cream 100% silk long underwear under all my clothes. I buy mine from Winter Silk and Terramar silk from Amazon.
The long johns are very thin and really do not make your clothes look bulky. I always wash all new clothes including silk several times in a perfume-free and dye-free detergent and rinse them twice before wearing them.
I recently ran across a company who sells 100% pure medical grade silk long underwear. Their product sounds pretty impressive, but the items are very expensive, so I have not been able to try them out. The name is Derma Silk they are located in Canada, the link is http://www.dermasilk.ca/
When summer comes I switch over to wearing well washed and rinsed 100% cotton fabrics in white and very pale colors. My favorite combination is a well washed white top with faded khaki bottoms. Some brands of blue jeans are better for my skin than others. The only way to know for sure is to try them. Levis 501 are suppose to use Indigo dye which may rub off on your skin, but should not be as irritating as synthetic dyes. I like to wear well washed Eddie Bauer jeans, they fit me well and do not irritate my skin.